1. Field of the Invention
This invention relates to a magnetic head device and a recording medium drive, which are suitable for application to a mass-storage floppy disk drive or the like. Specifically, this invention relates to a magnetic head device or the like wherein first and second rails are formed on a slider, a head chip for a standard recording density is provided on the first rail, a head chip for a high recording density is provided on the second rail, and the width of the second rail is set narrower than that of the first rail, whereby low-order compatibility is provided, and the amount of levitation of the second rail is limited to improve a recording-reproducing characteristic of the head chip for the high recording density.
2. Description of the Related Art
For example, a floppy disk having a larger capacity of several tens of Mbytes to several hundreds of Mbytes as compared with the capacity of a conventional floppy disk has been proposed as a removable disk-shaped recording medium. In this case, an increase in the capacity of the floppy disk is achieved by the integration of various techniques such as a material used for a recording medium, a structure of a head chip, the processing of a signal for reproduction, the presence or absence of a tracking servo.
As one of the mass-storage floppy disk drive, the floppy disk drive of levitation type has been proposed, which increases the number of revolutions of a disk and performs recording/reproduction of data in such a way that a magnetic head is slightly levitated from a recording surface of the disk.
The levitation-typed mass-storage floppy disk drive is one wherein the disk is rotated at a high speed and the resultant pressure based on airflow is used to levitate the magnetic head. A levitation system is a technique adopted in a hard disk drive. In practice, a slider with head chips incorporated therein is levitated.
The levitation-typed mass-storage floppy disk drive, which has already been proposed, has a problem in that it has no compatibility or low-order compatibility with the already-existing floppy disk drive. Thus, a problem arises in that a disk drive for a mass-storage floppy disk cannot be incorporated in a personal computer under the circumstances where the current floppy disk is used.
It is therefore an object of the present invention to provide a magnetic head device or the like having low-order compatibility and capable of improving a recording-reproducing characteristic of a head chip for a high recording density.
According to a first aspect of the present invention, we provide a magnetic head device comprising a magnetic head element including a slider, first and second rails provided on the slider in form protruded to a recording medium side so as to extend in a tangential direction of a track of the recording medium and be parallel with each other, a first head chip for recording and reproducing data in a state of being kept in contact with a recording surface of the recording medium and in a first recording density, said first head chip being provided substantially in the central position of the first rail as viewed in the tangential direction of the track, and a second head chip for recording and reproducing data in a state of being levitated from the recording surface of the recording medium and in a second recording density greater than the first recording density, said second head chip being provided in a position on the rear side of the second rail with respect to the tangential direction of the track, wherein the width of the second rail of the magnetic head element is narrower than that of the first rail thereof.
In this aspect, when data are recorded on and reproduced from a recording medium at a first recording density, e.g., a standard recording density, the recording/reproduction is performed by a first head chip in a state in which it is in contact with the recording surface of the recording medium. On the other hand, when data is recorded on and reproduced from the recording medium at a second recording density, e.g., a high recording density, the recording/reproduction is performed by a second head chip in a state in which it is levitated from the recording surface of the recording medium. Thus, the recording/reproduction can be effected even on the recording medium for the standard recording density as well as on the recording medium for the high recording density, whereby low-order compatibility is obtained. Since the width of the second rail is narrower than that of the first rail, the amount of levitation of a second rail with respect to the recording medium is limited as compared with a first rail. Thus, recording-reproducing characteristics of the second head chip with respect to the recording medium having the high recording density can be improved. Since respective outer edges of the first and second rails are processed into tapered form, the edges of the rails make it possible to lessen the scratching of the recording surface of the recording medium upon soft landing and seek operation.
According to the second aspect of the present invention, we provide A magnetic head device comprising first and second head portions disposed in an opposing relationship so as to interpose a recording medium therebetween, a magnetic head element, which constitutes each of the first and second head portions, including a slider, first and second rails provided on the slider in form protruded to the recording medium side so as to extend in a tangential direction of a track of the recording medium and be parallel with each other, and a head chip for recording and reproducing data in a state of being levitated from a recording surface of the recording medium and in a predetermined density, said head chip being provided in a position on the rear side of the second rail with respect to the tangential direction of the track, wherein the width of the second rail is narrower than that of the first rail, and wherein the first and second rails of the magnetic head element constituting the first head portion are opposite to the second and first rails of the magnetic head element constituting the second head portion.
In this second aspect, data are recorded on and reproduced from one recording surface of a recording medium by a first head portion, whereas data are recorded on and reproduced from the other recording surface thereof by a second head. When, in this case, the data are recorded on and reproduced from the recording medium, for example, at a high recording density, the recording/reproduction is made by a head chip in a state in which it is levitated from a recording surface of the recording medium. The amount of levitation of a second rail with respect to the recording medium can be reduced as compared with a first rail by setting the width of the second rail narrower than that of the first rail. Further, since first and second rails of a magnetic head element constituting a first head portion are opposed to second and first rails of a magnetic head element constituting a second head portion, the recording medium is deformed or each magnetic head element is further inclined so that the second rails approach the recording surface of the recording medium at the opposed rail portions. Thereby, the amount of levitation of each second rail with respect to the recording medium is further restrained. Accordingly, it is possible to further improve a recording-reproducing characteristic of each head chip with respect to the recording medium for the high recording density, for example.
Incidentally, head chips for respectively recording and reproducing data in a state of being in contact with recording surfaces of a recording medium and in a density lower than the predetermined density may be respectively provided substantially in the central positions of the first rails of the first and second head portions. Thus, when data are recorded on and reproduced from a recording medium for a standard recording density, for example, the recording/reproduction can be made by the head chips provided on first rails in a state in which they are in contact with the recording surfaces of the recording medium, whereby low-order compatibility is obtained.
According to the third aspect of this invention, we provide a recording medium drive comprising the magnetic head device as described in the above first aspect, a record processing circuit for generating record data to be recorded on the recording medium by the magnetic head device, and a reproduction processing circuit for processing reproduction data reproduced from the recording medium by the magnetic head device.
Since the recording medium drive is provided with the above magnetic head device, it has low-order compatibility and makes it possible to limit the amount of levitation of each second rail with respect to the recording medium and thereby improve a recording-reproducing characteristic of a high recording density head chip.
According the forth aspect of this invention, we provide a recording medium drive comprising the magnetic head device as described in the above second aspect, a record processing circuit for generating record data to be recorded on a recording medium by the magnetic head device, and a reproduction processing circuit for processing reproduction data reproduced from the recording medium by the magnetic head device.
Since the recording medium drive is provided with the magnetic head device as described in the above forth aspect, it makes it possible to limit the amount of levitation of each second rail with respect to the recording medium and thereby improve a recording-reproducing characteristic of a head chip for a high recording density, for example.